Nosocomial infections (NIs) remain an important cause of morbidity, mortality, and increased health care costs in hospitalized patients. This is particularly problematic in intensive care units (ICUs) where NIs occur in 25 to 35 % of ICU patients and account for approximately 25 % of all nosocomial infections in the hospital. In ICU patients, mechanical ventilation is an important risk factor for NIs. Further, since NIs are increasingly caused by multidrug-resistant bacteria, clinicians frequently prescribe broad spectrum antibiotic regimens. In turn, this sets the stage for pseudomembranous colitis (PMC), another potentially lethal NI. The prevention of NIs has the potential to improve patient outcomes and reduce the cost burden of increasingly broad spectrum, prolonged courses of antibiotics administered for suspected or confirmed infections.

Lactoferrin (LF), an 80-kDa, multifunctional glycoprotein of the transferrin family, is distributed widely in humans particularly in secretions of exocrine glands and specific neutrophil granules. The highest concentrations of LF are found in breast milk and colostrum. As an important component of the human innate immune system, it has many appealing properties that may prove effective for the prevention of NIs.

LF has the ability to bind iron, an important element for microbial growth, thereby reducing its availability to microorganisms and making it bacteriostatic. In addition, LF has bactericidal effects on microorganisms attributable to its highly cationic charged terminus, which binds to bacterial surfaces. The binding of LF to the bacterial surface destabilizes the bacterial outer membrane, thus enhancing bacterial susceptibility to osmotic shock, lysozyme, or other antimicrobial molecules. This antibacterial activity has been documented against many important human pathogens, including: Escherichia coli, Staphylococcus aureus, Klebsiella sp.,Acinetobacter sp., Pseudomonas sp., Salmonella sp., and Proteus sp. Additionally, LF has been shown to exhibit activity against Candida albicans and Candida krusei and to inhibit the formation of biofilms by Pseudomonas aeruginosa and oral bacteria.

Professor John Muscedere and his team are looking at at lactoferrin in the prevention of nosocomial infections in the critically ill. AOR provided the clinical trial material for this randomized double blind clinical study.